There are numerous prior art devices and methods for aiding a person in keeping track of time. Calendars used simply for keeping track of the passage of time have been known for millennia. Other calendar designs have incorporated figures or messages for aesthetic enhancement of the calendar. Many previous calendars have been designed which provide humorous, religious, or inspirational messages for a user associated with each day. For example, Christmas Advent calendars provide religious inspiration through messages and figures relating to the biblical teachings of the Christmas season.
U.S. Pat. No. 2,831,278, issued to R. H. Myers, on Apr. 22, 1958, presents a calendar structure, which permits a user to write personal reminder messages under a moveable tab covering each date on the monthly calendar. U.S. Pat. No. 5,207,580, issued to Victor J. Strecher, on May 4, 1993, presents a calendar manufactured with customized textual messages relating to a specific health or behavior modification goal for a particular person. Motivational messages as well as reminder messages are displayed in appropriate days of each related month. Specific days, months, and messages are unique to the particular peoples' behavior modification or health-related goal. U.S. Pat. No. 5,090,733, issued to R. Bussier, on Feb. 25, 1992, presents a calendar with inspirational and motivational messages indicating thoughts or actions for each day, the goal being inspiration for self-improvement. The messages are printed on moveable tabs, relating to sections of a picture so that as messages are added or revealed, a picture is being constructed to inspire the user to fulfill a personal goal. These past inventions are not associated with the timing of any specific event comprising part of a time interval but rather relate to abstractions, such as personal reminders, inspiration, or motivation. The time periods associated with these inventions are arbitrary in that they are not related to the timing of any particular event or interval. Therefore, a need was established for a calendar, which was useful to inform a user as to the progress of timing and development of a specific time constrained event or interval.
A first attempt at meeting this need was U.S. Pat. No. 5,443,288, issued to Barbara L. Miles, on Aug. 22, 1995, which is an advent calendar for educating an expectant mother as to the fetal development process and the associated milestones or the human gestation period. Unlike the present invention, the Miles device specifically informs a user regarding fetal development during a plurality of weeks of the human gestation period, and is not applicable to the instruction of children, whereas the present invention is specifically tailored to aiding a child in determining time intervals preceding a date of significance. Not only do the purpose and look of the present invention differ from the Miles device, but also the method of informing the user, the comprehension level of calendar information, and the arrangement of calendar elements and graphics. None of the above noted patents, taken either singly or in combination, are seen to disclose the specific arrangement of concepts disclosed by the present invention. Therefore, a need has been established for a calendar specifically tailored for instruction of a child that aids the child in determining time intervals preceding a date of significance, such as the number of days before a birthday.